Adding html content after an element using css

Adding html content after an element using css

like what the title says I'm trying to add a specific content to a part of
a page. Obviously this is a desperate resort because I'm unable to modify
the codes manually. So far this is what I have.
.paper-form
input[name="elements[bd67ba9a-507b-4214-98a3-5abd36562937]"]:after {
content:'test';
}
From what I did the name selector is working but once I added the :after
It just doesn't work. Can anyone tell me I'm not used to using pseudo
codes. Thanks in advance.